This present invention relates to use of natural flavidin as an antioxidant.
Antioxidants play a crucial role in preventing or delaying autoxidation and have attracted a lot of attention as food additives. The deterioration of food with time, results from its biological nature largely and is inevitable. During the production, processing, distribution, storage preceding and even during actual consumption food undergoes various modes of deterioration that involve biological changes by microbes as well as chemical changes. The latter is represented by enzymatic and non-enzymatic oxidation of lipids and phenolic substance, which cause undesirable changes in flavor, appearance, physical character, nutritional value and toxicity. Deoxygenation, airtight packing, and other techniques have solved some of these problems, but the role of antioxidants as either food constituents or as additives cannot be overlooked. Both synthetic and natural antioxidants are widely used in many food products.
The area of natural antioxidants has been developing since the past decade, mainly because of the increasing limitations on the use of synthetic antioxidants and enhanced public awareness of health issues. In general, natural antioxidants are preferred by consumers because they are considered environmental friendly. Commercial antioxidants are generally synthetic compounds and there has been a growing interest in replacing them with natural ingredients due to possible toxicity of synthetic antioxidants (J. Food Sci., 42, 1102, 1977) as shown by clinical studies (Toxicological aspects of antioxidants used as food additives, In-Food Antioxidants; Hudson, B. J. F., Ed.; Elsevier; London, 1990; p. 253). Further, the use of some common synthetic antioxidants such as butylated hydroxy anisole (BHA) and butylated hydroxytolune (BHT) has become a controversial issue because of adverse toxicological data (Food antioxidants, edited by Madhavi, Despande and Salunkhe, Marcel Dekker, Inc., New York 1995, p. 267). The use of natural antioxidants in food is limited due to the lack of knowledge about their molecular compositions, the content of active compounds in the raw materials and the availability of relevant toxicological data. Hence, evaluation of the antioxidative activity of naturally occurring substances has been of interest in recent years (Nahrung, 1996, 40, 261). Currently, the use of some naturally occurring antioxidants in preventive and therapeutic medicine is gaining popularity. Rosemary and Marjoram are known to contain powerful antioxidants. But these are not indigenous to India.
A literature survey revealed that, there is no report on the antioxidant activity of phenanthropyran type of compounds which are abundantly found in a few genera of family Orchidaceae. The family of Orchidaceae is one of the largest families of flowering plants. Orchids are most facinating by reason of their diversity and specialization in floral and regulative features. Members of Orchidaceae are widely distributed in all parts of the world with the greatest concentration being in tropics. About 860 species belonging to 132 genera grow in various regions of India. Particularly, the foot hill areas of Himalayas, western and eastern ghats are rich sources of orchids. Subtribes viz Dendrobium, Bulbophyllinae and Coelogyninae are reported to possess 9,10-dihydro-5H phenanthro-(4,5 bcd)-pyrans and pyrones. Flavidin (2,7-dihydroxy 9,10-dihydrophenanthro-4,5 bcd-pyran) is found in many of these subtribes, mainly in the species of Coelogyne genus (Phytochemistry, 28, 3031, 1989). The applicants, during their study found that these compounds exhibit anti-oxidant properties.
Accordingly, the main object of the invention is to provide materials capable of being used as anti-oxidants in food compositions or food products.
Another objective is to provide food compositions that contain natural flavidin (2,7-dihydroxy 9,10-dihydrophenanthro-4,5 bcd-pyran) compounds as anti-oxidants for preservation of food products.
Yet another object is to provide methods for preservation of food products employing natural flavidin compounds of the invention.